Web services may provide access to data, information, and other functionality to client or host devices on a network. A client device or host device may transmit a web service request, including a query for data or information, to a web service server. In response to receiving the web service request, the web service server may execute programming code for the web service and generate a web service response based on the received request. The server transmits the generated response, including data or information related to the query, back to the client device or host device. The client device or host device may communicate directly with the web service or may communicate with a web service application programming interface (API) associated with the web service.
Many networks provide extensible markup language (XML) based web services that may enable access to network data. For example, web services may be based on one or more network protocols designed to facilitate communications between users and web services servers. Examples of the network protocols may include, but are not limited to, the Simple Object Access Protocol (SOAP), the Representational State Transfer (REST) protocol, and the Hyper-Text Transfer Protocol (HTTP). The web services may also be designed to facilitate communications between a host or server and the web servers that host services for the host or server. A user (or host/server) may access a web service, for example through a web service application program or a web service API, which can provide one or more operations or functions (e.g., methods) for the user (or host/server) to use in accessing the web service. For example, a web-based catalog may provide services related to searching or browsing a catalog, selecting items from the catalog, performing checkout in order to purchase catalog items, etc. The programming code of a web service may be updated to provide new functionalities to users and client devices, to improve the efficiency of the web service (or associated web service API), etc., and when web service (or web service API) programming code is updated or improved, the web service (or web service API) may be tested to verify the compatibility of the service with different user devices.